Tesla's earnings beat—when Wall Street analysts expected a loss—didn't make a buyer out of RiskReversal's Dan Nathan.
"Elon Musk says what he wants to say," Nathan said. "Don't forget, people. This is the guy who said in the last couple of months that this stock's expensive here."
After Wednesday's market close, the electric-car company posted earnings of 2 cents a share vs. an estimated 1-cent loss, sending shares 7 percent higher in after-hours trading.
On CNBC's "Fast Money," Nathan said that he held "a small defined-risk trade in options" and expected the stock to decline.